The invention relates to a laundry drying device having a heat pump.
Fully automatic washer-dryers are known, which are provided with a compression heat pump so as to reduce the energy consumption during the drying process. The configuration comprising water condensation and resistance heating which is traditionally used in fully automatic washer-dryers is essentially replaced here by a closed refrigerant circuit filled with refrigerant comprising a compressor, evaporator, condenser and governor. On account of the restricted available space, only very specific arrangements are possible for the closed refrigerant circuit, without changing the overall device dimensions.
An arrangement of a compact unit for the refrigerant circuit on a base plate, which closes off the housing of the fully automatic washer-dryer towards the bottom, is known for a fully automatic washer-dryer VA-1000 by the Japanese company National. The following disadvantages in terms of energy result here during the drying process:
The air paths from the tub to the heat exchangers (evaporator, condenser) are very long. A precondensation of the warm and damp process air in the drying process results en route from the tub to the evaporator. This precondensation reduces the pump output within the refrigerant circuit, since less water per time unit precipitates out on the evaporator and thus less energy can also be pumped. Further losses develop from the condenser to the air inlet into the drum as a result of heat losses on the channel walls up until entry into the drum.